LAS VEGAS – For decades, the vulnerable desert tortoise has led a sheltered existence.

Developers have taken pains to keep the animal safe. It's been protected from meddlesome hikers by the threat of prison time. And wildlife officials have set the species up on a sprawling conservation reserve outside Las Vegas.

But the pampered desert dweller now faces a threat from the very people who have nurtured it.

Federal funds are running out at the Desert Tortoise Conservation Center and officials plan to close the site and euthanize hundreds of the tortoises they've been caring for since the reptiles were added to the endangered species list in 1990.

Officials expect to put down more than half the 1,400 tortoises at the research and holding facility in the coming months in preparation for closure at the end of 2014.